Device and method using magnetic pattern on disk

ABSTRACT

As embodiment of the invention relates to a device for performing NMR or ESR analysis. The device comprises a detection unit, a magnet, and a disk having a magnetic pattern. The detection unit comprises a sample holding space for holding a sample and a microcoil for detecting NMR or ESR signals generated within the sample. The magnet generates a static magnetic field within the sample. The disk and magnetic pattern, when rotating, generate an excitation magnetic field, which, together with the static magnetic field, creates an NMR or ESR within the sample. Other embodiments of the invention encompass methods for performing NMR or ESR analysis using the device and methods of making such devices.

RELATED APPLICATIONS

This application is related to application Ser. No. 11/319,755 (AttorneyDocket No. 070702001300), entitled “Integrated on-chip NMR and ESRdevice and method for making and using the same;” and to applicationSer. No. 11/319,773 (Attorney Docket No. 070702001800), entitled“Portable NMR device and method for making and using the same,” bothfiled Dec. 29, 2005, and both of which are incorporated herein byreference.

FIELD OF INVENTION

The embodiments of the invention relate to NMR or ESR devices, methodsof making such devices, and methods of performing NMR or ESR analysisusing such devices. More specifically, the embodiments relate to devicesand methods that combine on-chip NMR or ESR technology and magneticpatterns on a rotatable disk that perform versatile and/or convenientNMR or ESR analysis with design flexibility. The invention transcendsseveral scientific disciplines such as nuclear chemistry and physics,engineering, microelectronics, analytical chemistry, and medicaldiagnostics.

BACKGROUND

Nuclear Magnetic Resonance (NMR) and, to a lesser degree, Electron SpinResonance (ESR) are widely used in chemical analysis and medicaldiagnostics. NMR is a physical phenomenon that occurs when the nuclei ofcertain atoms that are subject to a static magnetic field are exposed toa second oscillating magnetic field. The oscillating magnetic field,often generated by an electromagnet, is also called a perturbing orexcitation magnetic field. Some nuclei experience this phenomenon, andothers do not, dependent upon whether they possess a property calledspin. ESR, which is also called Electron Paramagnetic Resonance (EPR),is a physical phenomenon analogous to NMR, but instead of the spins ofthe atom's nuclei, electron spins are excited in an ESR. Because of thedifference in mass between nuclei and electrons, weaker static magneticfields and higher frequencies for the oscillating magnetic fields areused, compared to NMR.

The current devices using the NMR or ESR principle have at least twodrawbacks. First, the sizes of the devices are too big. For example,typical NMR spectrometers are bench-top models. Thus, the currentspectrometers are too big to be used in field applications or at homeenvironment. Second, the current NMR devices require a large amount ofsample, which not only is infeasible for certain applications, but alsohinders activities such as mixing and heating of the sample required formany analysis. Thus, there is a need for a miniaturized, integrated, andversatile NMR or ESR device that can perform on-site, flexible, rapid,sensitive, and/or efficient analysis.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an embodiment of the invention that comprises a diskwith magnetic patterns, a resonance detector unit, a servo-controlmechanism, and a signal processing unit.

FIG. 2 illustrates a more detailed cross-section view of the resonancedetector unit that comprises a substrate, a sample holding space,permanent magnets, and microcoils.

FIG. 3 illustrates a more detailed top-down view of the resonancedetector unit.

FIG. 4 illustrates a more detailed view of the disk with magneticpatterns.

DETAILED DESCRIPTION

The embodiments of the invention relate to a device comprising anon-chip NMR or ESR detection unit, a magnet, and a rotatable disk with amagnetic pattern for performing chemical analysis and medicaldiagnostics. Specifically, the detection unit comprises a sample holdingspace and an associated microcoil; the magnet is to generate a staticmagnetic field across the sample holding space; and the magnetic patternon the rotating disk is to generate an excitation magnetic field acrossthe sample holding space such that an NMR or ESR is generated within asample contained in the space. The signals from the NMR or SER aredetected by the microcoil. The device may further compriseservo-mechanical components and mechanisms to control the locations andmovements of the detection unit, the magnet, and the disk.

The embodiments of the invention also relate to a method of performingNMR or ESR analysis using the device and to a method of making thedevice. The detection unit of the embodiments of the invention may bepart of an integrated device that also serves as a microarray ormacroarray, an integrated circuit, a microfluidic device, a MEMS, or acombination. Therefore, samples contained or processed by the device maybe also analyzed by the integrated NMR or ESR device and the signalsprocessed for analysis. If necessary, the signals from the NMR may betransmitted to another device for further analysis, such as NMR or ESRspectroscopy and Magnetic Resonance Imaging (MRI).

As used in the specification and claims, the singular forms “a”, “an”and “the” include plural references unless the context clearly dictatesotherwise. For example, the term “an array” may include a plurality ofarrays unless the context clearly dictates otherwise.

A “disk” or “disc” refers to an object that has a flattened cylindershape. Although a disk used herein is usually rigid, it may also beflexible, such as being bendable. The disk could be made from manysuitable materials, including but not limited to metals, polymers,silicon, and glass. The size and thickness of the disk will depend uponthe specific device and its applications desired. Specific types ofdisks commercially available and readily adaptable include opticaldiscs, compact discs (CDs), digital versatile discs (DVDs), laserdisc,magneto-optical discs, minidisk, digital multilayer disks, fluorescentmultilayer disc, universal media discs, floppy disks, and hard drivedisks. The disks should be adaptable to mechanical and/or electricalcontrols such that they are able to rotate at controlled and desiredspeeds and be placed at desired locations. Further, magnetic materialsshould be able to be attached to the disks to form desired patterns.

A “magnetic pattern” on a disk refers to one or more of magneticmaterials or “magnetic members” attached on a surface of the diskaccording to a pre-designed fashion. The magnetic members are usuallydiscretely located on the surface, although they may also beinterconnected in certain situations. A magnetic member is usually smallin size and can be defined by the area that it occupies on the surfaceand the thickness, or the biggest perpendicular distance from any pointon the member to the surface of the disk. A magnetic member is furtherdefined by its distance to the center of the disk. Thus, when the diskis rotating, a certain magnetic member will rotate at a specific linearspeed, based on the rotating speed of the disk and the member's distancefrom the center of the disk. The rotation will also create a uniquecircular “track” for a specific magnetic member. As discussed herein, arotating magnetic member is capable of generating an excitation magneticfield within a sample in a sample holding space that is on or near thetrack of the magnetic member.

“Disk rotation,” “rotation” or “rotating” refers to turning of a diskaround its center, or imaginative center, in a substantially smoothfashion and without noticeable wobbling. In other words, when rotating,a disk should remain substantially within a plane. The speed of a diskrotation can be measured by revolution per minute or “rpm.” The movementof an object, such as a magnetic member, on the disk can be measured bythe linear travel speed, which can be determined by the disk's rotationspeed and the distance of the object to the center of the disk. Asdiscussed herein, a rotating magnetic member can generate magneticpulses, and the ability of the magnetic member to generate an excitationmagnetic field depends, in part, on its linear travel speed.

A “substrate” refers to a material or a combination of materials uponand/or within which other or additional materials are formed, attached,or otherwise associated with according to a predetermined fashion. Asubstrate often provides physical and functional support to the other oradditional materials such that, together, they form part or whole of afunctional device. A substrate may be a combination of two or more othersubstrates, which, due to the combination, have become an identifiablenew substrate. In the embodiments of the invention, the substrate maycomprise metal, silicon, glass, or polymeric materials. In more specificembodiments, the substrate comprises an integrated material, such as amicrofluidic device or an integrated circuit die.

A “microcoil” is a coil, or one or more connected loops, having at leastone dimension in the micrometer (μm), or less than 10⁻³ meter (mm),scale. A microcoil usually comprises a thin material wound or gatheredaround a center or an imaginative center into spiral, helical or othershapes. A microcoil is defined by the material itself, the shape of thewindings, and the separation between each windings. Solenoid typemicrocoils are multiple spiral wire loops, which may or may not bewrapped around a metallic core. A Solenoid type microcoil produces amagnetic field when an electrical current is passed through it and cancreate controlled magnetic fields. A Solenoid type microcoil can producea uniform magnetic field in a predetermined volume of space. A “planar”microcoil is a microcoil with its windings substantially remained in anactual or imaginative plane.

A “microchannel” is a channel, groove, or conduit having at least onedimension in the micrometer (μm), or less than 10⁻³ meter (mm), scale.Although microchannels are typically straight along their length, theymay contain angles and curves of different degrees along their length.Although the microchannels typically have rectangular cross-sections,they may also have other shapes of cross-sections, such as circle. Themicrochannels are usually suitable for fluidic communications, such ascarrying through a biological liquid. The microchannels are often partof an integrated device, such a microfluidic device or an integratedcircuit such that liquid flowing through the microchannels are in acontrolled pattern and able to be analyzed as desired.

As used in the embodiments of the invention, “associated with” or “inassociation with” means that two or more objects are so situated thatthe desired results or effects are achieved. For example, a microcoil is“associated” with a space for holding a liquid sample when the microcoilis so situated that it will achieve the desired effect of generating anexcitation magnetic field and/or detecting an NMR or ESR signal withinat least a portion of a sample in the space. Similarly a magnet is also“associated” with the space and the microcoil if it is capable ofgenerating a static magnetic field across at least a portion of thespace. A number of factors will be considered when associating themicrocoil or the magnet with the space, including whether the magnet ison the detection unit substrate, the sizes and shapes of the substrate,the type and size of the microcoil and the magnet, the size and locationof the associated space, the desired strengths of the excitationmagnetic field and the static magnetic field and, and the volume withinwhich the desired NMR or ESR will be effectuated. As disclosed herein,the specific locations of the magnet and microcoil on the detectionunit, or substrate, will be determined based on the specific analysisdesired by a person skilled in the art.

As used herein, “dimension” or “dimensions” are the parameters ormeasurements required to define the shape and/or size, such as height,width, and length, of an object. As used herein, the dimension of atwo-dimensional object, such as a rectangle, a polygon, or a circle, isthe longest straight-line distance between any two points on the object.Therefore the dimension of a circle is its diameter; a rectangle itsdiagonal, and a polygon its longest diagonal. The dimension of athree-dimensional object is the longest straight-line distance betweenany two points on the object. The dimensions used herein are usuallymeasured by centimeters (cm), millimeters (mm), and micrometers (μm),and nanometers (nm).

A “microfluidic device” is a device that has one or more microchannels.A microfluidic device may be part of an integrated device, such as anintegrated separation or detection equipment or an integrated circuit.Fluids used in microfluidic devices include whole blood samples,bacterial cell suspensions, protein or antibody solutions and variousbuffers and saline. Microfluidic devices can be used to obtain manyinteresting measurements, including fluid mechanical properties,cellular and molecular diffusion coefficients, fluid viscosity, pHvalues, chemical and biological binding coefficients and enzyme reactionkinetics. Other applications for microfluidic devices include cell andmolecule detection and separation, capillary electrophoresis,isoelectric focusing, immunoassays, flow cytometry, sample injection ofproteins for analysis via mass spectrometry, DNA analysis, cellmanipulation, and cell separation. In the embodiment of the invention,magnetic materials and technologies are incorporated into themicrofluidic devices for applications such as cell and biomoleculedetection and separation.

The use of microfluidic devices to conduct biomedical assays has manysignificant advantages. First, because the volume of fluids within thesechannels is very small, usually several nano-liters, the amount ofreagents and analytes required for the assays is quite small. This isespecially significant for expensive reagents. The fabricationstechniques used to construct microfluidic devices, discussed in moredetails herein, are relatively inexpensive and are very amenable both tohighly elaborated, multiplexed devices and also to mass production, suchas in an integrated circuit die. In manners similar to that formicroelectronics, microfluidic technologies also enable the fabricationof highly integrated devices for performing different functions on thesame substrate chip. Embodiments of the invention helps createintegrated, portable clinical diagnostic devices for home and bedsideuse, thereby eliminating time consuming laboratory analysis procedures.

In the embodiments of the invention, the flow of a fluid through amicrofluidic channel, or microchannel, can be characterized by theReynolds number (Re), defined asRe=LV _(avg)ρ/μwhere L is the most relevant length scale, μ is the fluid viscosity, ρis the fluid density, and V_(avg) is the average velocity of the flow.For many microchannels, including channels with a rectangularcross-section, L is equal to 4A/P where A is the cross-sectional area ofthe channel and P is the wetted perimeter of the channel. Due to thesmall dimensions of microchannels, the Re is usually much less than 100,often less than 1.0. In this Reynolds number regime, flow is completelylaminar and no turbulence occurs. The transition to turbulent flowgenerally occurs in the range of Reynolds number 2000. Laminar flowprovides a means by which molecules can be transported in a relativelypredictable manner through microchannels.

As used herein, “magnetic,” “magnetic effect,” and “magnetism” refer tothe phenomena by which one material exert an attractive or repulsiveforce on another material. Although theoretically all materials areinfluenced to one degree or another by magnetic effect, those skilled inthe art understand that magnetic effect or magnetism is only recognizedfor its detectability under the specific circumstance.

As used herein, a “permanent magnet” is a material that has a magneticfield without relying upon outside influences. Due to their unpairedelectron spins, some metals are magnetic when found in their naturalstates, as ores. These include iron ore (magnetite or lodestone),cobalt, and nickel. A “paramagnetic material” refers to a material thatattracts and repels like normal magnets when subject to a magneticfield. Paramagnetic materials include aluminum, barium, platinum, andmagnesium. A “ferromagnetic material” is a material that can exhibit aspontaneous magnetization. Ferromagnetism is one of the strongest formsof magnetism and is the basis for all permanent magnets. Ferromagneticmaterials include iron, nickel, and cobalt. A “superparamagneticmaterial” is a magnetic material that exhibits a behavior similar tothat of a paramagnetic material at temperatures below the Curie or theNeel temperature.

An “electromagnet” is a type of magnet in which the magnetic field isproduced by a flow of electric current. The magnetic field disappearswhen the current ceases. A simple type of electromagnet is a coiledpiece of wire that is electrically connected. An advantage of anelectromagnet is that the magnetic field can be rapidly manipulated overa wide range by controlling the electric current. In the embodiments ofthe invention, ferromagnetic or non-magnetic materials are used to formthe electromagnets.

An “array,” “macroarray” or “microarray” is an intentionally createdcollection of substances, such as molecules, openings, microcoils,detectors and/or sensors, attached to or fabricated on a substrate orsolid surface, such as glass, plastic, silicon chip or other materialforming an array. The arrays can be used to measure the expressionlevels of large numbers, e.g., tens, thousands or millions, of reactionsor combinations simultaneously. An array may also contain a small numberof substances, e.g., a few or a dozen. The substances in the array canbe identical or different from each other. The array can assume avariety of formats, e.g., libraries of soluble molecules; libraries ofcompounds tethered to resin beads, silica chips, or other solidsupports. The array could either be a macroarray or a microarray,depending on the size of the pads on the array. A macroarray generallycontains pad sizes of about 300 microns or larger and can be easilyimaged by gel and blot scanners. A microarray would generally containpad sizes of less than 300 microns.

An array of microcoils is a collection of microcoils fabricated on asubstrate, such as silicon, glass, or polymeric substrate. Each of themicrocoils may be associated or corresponded with a sample space acrosswhich the microcoil is capable of generating an oscillating magneticfield as part of an NMR analysis. The sample space may be a space forholding a liquid sample or a spot for immobilizing certain molecules,such as DNAs and proteins. The microcoil arrays may be a microarray or amacroarray depending on the sizes or the microcoils and the associatedsample spaces.

A DNA microarray is a collection of microscopic DNA spots attached to asolid surface forming an array. DNA microarrays can be used to measurethe expression levels of large numbers of genes simultaneously. In a DNAmicroarray, the affixed DNA segments are known as probes, thousands ofwhich can be used in a single DNA microarray. Measuring gene expressionusing microarrays is relevant to many areas of biology and medicine,such as studying treatments, disease and developmental stages.

“Solid support” and “support” refer to a material or group of materialshaving a rigid or semi-rigid surface or surfaces. In some aspects, atleast one surface of the solid support will be substantially flat,although in some aspects it may be desirable to physically separatesynthesis regions for different molecules with, for example, wells,raised regions, pins, etched trenches, or the like. In certain aspects,the solid support(s) will take the form of beads, resins, gels,microspheres, or other geometric configurations.

The term “molecule” generally refers to a macromolecule or polymer asdescribed herein. However, microchannels or arrays comprising singlemolecules, as opposed to macromolecules or polymers, are also within thescope of the embodiments of the invention.

A “macromolecule” or “polymer” comprises two or more monomers covalentlyjoined. The monomers may be joined one at a time or in strings ofmultiple monomers, ordinarily known as “oligomers.” Thus, for example,one monomer and a string of five monomers may be joined to form amacromolecule or polymer of six monomers. Similarly, a string of fiftymonomers may be joined with a string of hundred monomers to form amacromolecule or polymer of one hundred and fifty monomers. The termpolymer as used herein includes, for example, both linear and cyclicpolymers of nucleic acids, polynucleotides, polynucleotides,polysaccharides, oligosaccharides, proteins, polypeptides, peptides,phospholipids and peptide nucleic acids (PNAs). The peptides includethose peptides having either α-, β-, or ω-amino acids. In addition,polymers include heteropolymers in which a known drug is covalentlybound to any of the above, polyurethanes, polyesters, polycarbonates,polyureas, polyamides, polyethyleneimines, polyarylene sulfides,polysiloxanes, polyimides, polyacetates, or other polymers which will beapparent upon review of this disclosure.

The term “biomolecule” refers to any organic molecule that is part of orfrom a living organism. Biomolecules include a nucleotide, apolynucleotide, an oligonucleotide, a peptide, a protein, a ligand, areceptor, among others. A “complex of a biomolecule” refers to astructure made up of two or more types of biomolecules. Examples of acomplex of biomolecule include a cell or viral particles.

As used herein, “biological cells” and “cells” are interchangeable,unless otherwise clearly indicated, and refer to the structural andfunctional units of all living organisms, sometimes called the “buildingblocks of life.” Cells, as used herein include bacteria, fungi, andanimal mammalian cells. Specifically included are animal blood cells,such as red blood cells, white blood cells, and platelets.

The term “target,” “target molecule,” or “target cell” refers to amolecule or biological cell of interest that is to be analyzed ordetected, e.g., a nucleotide, an oligonucleotide, a polynucleotide, apeptide, a protein, or a blood cell. The target or target molecule couldbe a small molecule, biomolecule, or nanomaterial such as but notnecessarily limited to a small molecule that is biologically active,nucleic acids and their sequences, peptides and polypeptides, as well asnanostructure materials chemically modified with biomolecules or smallmolecules capable of binding to molecular probes such as chemicallymodified carbon nanotubes, carbon nanotube bundles, nanowires andnanoparticles. The target molecule or cell may be magnetically tagged,or labeled to facilitate their detection and separation.

The term “probe” or “probe molecule” refers to a molecule that binds toa target molecule or cell for the analysis of the target. The probe orprobe molecule is generally, but not necessarily, has a known molecularstructure or sequence. The probe or probe molecule is generally, but notnecessarily, attached to a solid support of the microfluidic device orarray. The probe or probe molecule is typically a nucleotide, anoligonucleotide, a polynucleotide, a peptide, or a protein, including,for example, cDNA or pre-synthesized polynucleotide deposited on thearray. Probes molecules are biomolecules capable of undergoing bindingor molecular recognition events with target molecules or cells. A probeor probe molecule can be a capture molecule.

The term “capture molecule” refers to a molecule that is immobilized ona surface. The capture molecule is generally, but not necessarily, bindsto a target or target molecule or cell. The capture molecule istypically a nucleotide, an oligonucleotide, a polynucleotide, a peptide,or a protein, but could also be a small molecule, biomolecule, ornanomaterial such as but not necessarily limited to a small moleculethat is biologically active, nucleic acids and their sequences, peptidesand polypeptides, as well as nanostructure materials chemically modifiedwith biomolecules or small molecules capable of binding to a targetmolecule that is bound to a probe molecule to form a complex of thecapture molecule, target molecule and the probe molecule. The capturemolecule may be magnetically or fluorescently labeled DNA or RNA. Inspecific embodiments of the invention, the capture molecule may beimmobilized on the surface of a magnetic tunnel junction sensor, whichitself is part of an integrated device, such as a microfluidic device oran integrated circuit. The capture molecule may or may not be capable ofbinding to just the target molecule or cell, or just the probe molecule.

The terms “die,” “polymer array chip,” “DNA array,” “array chip,” “DNAarray chip,” or “bio-chip” are used interchangeably and refer to acollection of a large number of probes arranged on a shared substratewhich could be a portion of a silicon wafer, a nylon strip or a glassslide.

The term “nucleotide” includes deoxynucleotides and analogs thereof.These analogs are those molecules having some structural features incommon with a naturally occurring nucleotide such that when incorporatedinto a polynucleotide sequence, they allow hybridization with acomplementary polynucleotide in solution. Typically, these analogs arederived from naturally occurring nucleotides by replacing and/ormodifying the base, the ribose or the phosphodiester moiety. The changescan be tailor-made to stabilize or destabilize hybrid formation, or toenhance the specificity of hybridization with a complementarypolynucleotide sequence as desired, or to enhance stability of thepolynucleotide.

The term “polynucleotide” or “nucleic acid” as used herein refers to apolymeric form of nucleotides of any length, either ribonucleotides ordeoxyribonucleotides, that comprise purine and pyrimidine bases, orother natural, chemically or biochemically modified, non-natural, orderivatized nucleotide bases. Polynucleotides of the embodiments of theinvention include sequences of deoxyribopolynucleotide (DNA),ribopolynucleotide (RNA), or DNA copies of ribopolynucleotide (cDNA)which may be isolated from natural sources, recombinantly produced, orartificially synthesized. A further example of a polynucleotide of theembodiments of the invention may be polyamide polynucleotide (PNA). Thepolynucleotides and nucleic acids may exist as single-stranded ordouble-stranded. The backbone of the polynucleotide can comprise sugarsand phosphate groups, as may typically be found in RNA or DNA, ormodified or substituted sugar or phosphate groups. A polynucleotide maycomprise modified nucleotides, such as methylated nucleotides andnucleotide analogs. The sequence of nucleotides may be interrupted bynon-nucleotide components. The polymers made of nucleotides such asnucleic acids, polynucleotides and polynucleotides may also be referredto herein as “nucleotide polymers.

When the biomolecule or macromolecule of interest is a peptide, theamino acids can be any amino acids, including α, β, or ω-amino acids.When the amino acids are α-amino acids, either the L-optical isomer orthe D-optical isomer may be used. Additionally, unnatural amino acids,for example, β-alanine, phenylglycine and homoarginine are alsocontemplated by the embodiments of the invention. These amino acids arewell-known in the art.

A “peptide” is a polymer in which the monomers are amino acids and whichare joined together through amide bonds and alternatively referred to asa polypeptide. In the context of this specification it should beappreciated that the amino acids may be the L-optical isomer or theD-optical isomer. Peptides are two or more amino acid monomers long, andoften more than 20 amino acid monomers long.

A “protein” is a long polymer of amino acids linked via peptide bondsand which may be composed of two or more polypeptide chains. Morespecifically, the term “protein” refers to a molecule composed of one ormore chains of amino acids in a specific order; for example, the orderas determined by the base sequence of nucleotides in the gene coding forthe protein. Proteins are essential for the structure, function, andregulation of the body's cells, tissues, and organs, and each proteinhas unique functions. Examples are hormones, enzymes, and antibodies.

The term “sequence” refers to the particular ordering of monomers withina macromolecule and it may be referred to herein as the sequence of themacromolecule.

The term “hybridization” refers to the process in which twosingle-stranded polynucleotides bind non-covalently to form a stabledouble-stranded polynucleotide; triple-stranded hybridization is alsotheoretically possible. The resulting (usually) double-strandedpolynucleotide is a “hybrid.” The proportion of the population ofpolynucleotides that forms stable hybrids is referred to herein as the“degree of hybridization.” For example, hybridization refers to theformation of hybrids between a probe polynucleotide (e.g., apolynucleotide of the invention which may include substitutions,deletion, and/or additions) and a specific target polynucleotide (e.g.,an analyte polynucleotide) wherein the probe preferentially hybridizesto the specific target polynucleotide and substantially does nothybridize to polynucleotides consisting of sequences which are notsubstantially complementary to the target polynucleotide. However, itwill be recognized by those of skill that the minimum length of apolynucleotide desired for specific hybridization to a targetpolynucleotide will depend on several factors: G/C content, positioningof mismatched bases (if any), degree of uniqueness of the sequence ascompared to the population of target polynucleotides, and chemicalnature of the polynucleotide (e.g., methylphosphonate backbone,phosphorothiolate, etc.), among others.

Methods for conducting polynucleotide hybridization assays have beenwell developed in the art. Hybridization assay procedures and conditionswill vary depending on the application and are selected in accordancewith the general binding methods known in the art.

It is appreciated that the ability of two single strandedpolynucleotides to hybridize will depend upon factors such as theirdegree of complementarity as well as the stringency of the hybridizationreaction conditions.

As used herein, “stringency” refers to the conditions of a hybridizationreaction that influence the degree to which polynucleotides hybridize.Stringent conditions can be selected that allow polynucleotide duplexesto be distinguished based on their degree of mismatch. High stringencyis correlated with a lower probability for the formation of a duplexcontaining mismatched bases. Thus, the higher the stringency, thegreater the probability that two single-stranded polynucleotides,capable of forming a mismatched duplex, will remain single-stranded.Conversely, at lower stringency, the probability of formation of amismatched duplex is increased.

The appropriate stringency that will allow selection of aperfectly-matched duplex, compared to a duplex containing one or moremismatches (or that will allow selection of a particular mismatchedduplex compared to a duplex with a higher degree of mismatch) isgenerally determined empirically. Means for adjusting the stringency ofa hybridization reaction are well-known to those of skill in the art.

A “ligand” is a molecule that is recognized by a particular receptor.Examples of ligands that can be investigated by this invention include,but are not restricted to, agonists and antagonists for cell membranereceptors, toxins and venoms, viral epitopes, hormones, hormonereceptors, peptides, enzymes, enzyme substrates, cofactors, drugs (e.g.opiates, steroids, etc.), lectins, sugars, polynucleotides, nucleicacids, oligosaccharides, proteins, and monoclonal antibodies.

A “receptor” is a molecule that has an affinity for a given ligand.Receptors may-be naturally-occurring or manmade molecules. Also, theycan be employed in their unaltered state or as aggregates with otherspecies. Receptors may be attached, covalently or noncovalently, to abinding member, either directly or via a specific binding substance.Examples of receptors which can be employed by this invention include,but are not restricted to, antibodies, cell membrane receptors,monoclonal antibodies and antisera reactive with specific antigenicdeterminants (such as on viruses, cells or other materials), drugs,polynucleotides, nucleic acids, peptides, cofactors, lectins, sugars,polysaccharides, cells, cellular membranes, and organelles. Receptorsare sometimes referred to in the art as anti-ligands. As the term“receptors” is used herein, no difference in meaning is intended. A“Ligand Receptor Pair” is formed when two macromolecules have combinedthrough molecular recognition to form a complex.

The term “chip” or “microchip” refers to a small device or substratethat comprises components for performing certain functions. A chipincludes substrates made from silicon, glass, metal, polymer, orcombinations and capable of functioning as a microarray, a macroarray, amicrofluidic device, a MEMS, and/or an integrated circuit. A chip may bea microelectronic device made of semiconductor material and having oneor more integrated circuits or one or more devices. A “chip” or“microchip” is typically a section of a wafer and made by slicing thewafer. A “chip” or “microchip” may comprise many miniature transistorsand other electronic components on a single thin rectangle of silicon,sapphire, germanium, silicon nitride, silicon germanium, or of any othersemiconductor material. A microchip can contain dozens, hundreds, ormillions of electronic components. In the embodiments of the invention,as discussed herein, microchannels, microfluidic devices, and magnetictunnel junction sensors can also be integrated into a microchip.

“Micro-Electro-Mechanical Systems (MEMS)” is the integration ofmechanical elements, sensors, actuators, and electronics on a commonsilicon substrate through microfabrication technology. While theelectronics are fabricated using integrated circuit (IC) processsequences (e.g., CMOS, Bipolar, or BICMOS processes), themicromechanical components could be fabricated using compatible“micromachining” processes that selectively etch away parts of thesilicon wafer or add new structural layers to form the mechanical andelectromechanical devices. Microelectronic integrated circuits can bethought of as the “brains” of a system and MEMS augments thisdecision-making capability with “eyes” and “arms”, to allow Microsystemsto sense and control the environment. Sensors gather information fromthe environment through measuring mechanical, thermal, biological,chemical, optical, and magnetic phenomena. The electronics then processthe information derived from the sensors and through some decisionmaking capability direct the actuators to respond by moving,positioning, regulating, pumping, and filtering, thereby controlling theenvironment for some desired outcome or purpose. Because MEMS devicesare manufactured using batch fabrication techniques similar to thoseused for integrated circuits, unprecedented levels of functionality,reliability, and sophistication can be placed on a small silicon chip ata relatively low cost. In the embodiments of the invention, as discussedherein, MEMS devices are further integrated with microchannels,microfluidic devices, and/or magnetic tunnel junction sensors, suchthat, together, they perform separation and detection function forbiological cells and biomolecules.

“Microprocessor” is a processor on an integrated circuit (IC) chip. Theprocessor may be one or more processor on one or more IC chip. The chipis typically a silicon chip with thousands of electronic components thatserves as a central processing unit (CPU) of a computer or a computingdevice.

A “nanomaterial” as used herein refers to a structure, a device or asystem having a dimension at the atomic, molecular or macromolecularlevels, in the length scale of approximately 1-1000 nanometer (nm)range. Preferably, a nanomaterial has properties and functions becauseof the size and can be manipulated and controlled on the atomic level.

The term “complementary” refers to the topological compatibility ormatching together of interacting surfaces of a ligand molecule and itsreceptor. Thus, the receptor and its ligand can be described ascomplementary, and furthermore, the contact surface characteristics arecomplementary to each other.

One embodiment of the invention relates to a device for performing NMRor ESR analysis. The device comprises a detection unit, a magnet, and adisk comprising a magnetic pattern. In the embodiment, the detectionunit comprises a microcoil and a space for holding a sample; the magnetis to generate a static magnetic field across at least a portion of thespace; and the magnetic pattern on the disk is to generate an excitationmagnetic field across at least a portion of the space. According to theembodiment, the static magnetic field and the excitation magnetic fieldare capable of creating Nuclear Magnetic Resonance (NMR) or ElectronSpin Resonance (ESR) within a sample contained in the space; and whereinthe microcoil is capable of detecting signals from the NMR or ESR.

In one embodiment, the detection unit integrates a sample holding spaceand a microcoil for detecting NMR or ESR signals occur within a samplein the space. The sample holding space and the microcoil may besupported by or integrated into a substrate. The magnet for generatingthe necessary static magnetic field can be placed either on thesubstrate or at a location near the substrate. The magnetic pattern onthe disk, when rotating at a pre-designed speed, generates a excitationmagnetic field with a sample in the space.

In a specific embodiment of the invention, the detection unit or thesubstrate comprises silicon, glass, a polymeric material, metal, or acombination thereof. More specifically, the detection unit may eithercomprise or be connected to an integrated circuit, a MEMS device, amicroarray, a macroarray, a multi-well plate, a microfluidic device, ora combination thereof. In other words, the embodiment can be integratedinto or connected to a wide range of materials used in a variety ofexisting devices.

Silicon is a suitable material for forming micro-channels coupled withmicroelectronics or other microelectromechanical systems (MEMS). It alsohas good stiffness, allowing the formation of fairly rigidmicrostructures, which can be useful for dimensional stability. In aspecific embodiment of the invention, the detection unit or substratecomprises an integrated circuit (IC), a packaged integrated circuit,and/or an integrated circuit die. For example, the substrate may be apackaged integrated circuit that comprises a microprocessor, a networkprocessor, or other processing device. The substrate may be constructedusing, for example, a Controlled Collapse Chip Connection (or “C4”)assembly technique, wherein a plurality of leads, or bond pads areinternally electrically connected by an array of connection elements(e.g., solder bumps, columns).

Specific materials useful as the substrate also include, but not limitedto, polystyrene, polydimethylsiloxane (PDMS), glass, chemicallyfunctionalized glass, polymer-coated glass, nitrocellulose coated glass,uncoated glass, quartz, natural hydrogel, synthetic hydrogel, plastics,metals, and ceramics. The substrate may comprise any platform or devicecurrently used for carrying out immunoassays, DNA or protein microarrayanalysis. Thus, the substrate may comprise a microarray or a macroarray,a multi-well plate, a microfluidic device, or a combination thereof.

In another embodiment, the detection unit comprises circuitry that iscapable of amplifying or processing the NMR or ESR signals detected bythe microcoil. Any suitable conventional circuits may be used andintegrated into the substrate for amplifying and/or processing,including filtering, the NMR or ESR signals detected and collected bythe microcoil. The integrated circuitry may be able to generate NMR orESR spectra independently or connected to an external device forgenerating the device.

In another embodiment of the invention, the sample is a liquid, a gel, asolid, a gas, or a mixture thereof. Therefore, the embodiment of theinvention can accommodate samples in different physical states. In aspecific embodiment, the sample is a liquid or in a liquid or solutionstate. In another embodiment, the space for holding a sample comprises areservoir, a microchannel, an opening, a surface, or a combinationthereof. The embodiment accommodates a variety of applications in whichan NMR or ESR is involved. For example, the sample holding space may bea reservoir, an opening void, or a surface that can hold a liquidsample. In such cases, the sample holding space may be an open reservoiror surface, or a substantially closed void with an opening for sampleinput. The design of the space depends not only on the specific analysisto be done, but also on how to best situate and design the sampleholding space in relation to the associated magnet and microcoil, asdiscussed herein.

According another embodiment, the space for holding a sample, such as aliquid sample, may also be the whole or part of a microchannelfabricated on the detection unit, or substrate. Depending on thespecific requirement, the microchannel may be open (a trench) or closed.The microchannel typically comprises an inlet and an outlet, but mayalso comprise other opening for fluidic communication. In anotherembodiment, the microchannel comprise two or more inlets and at leastone outlet such that different reactants may be introduced into thechannel from different inlets and mixed at a mixing section within thechannel for specific chemical reaction. Furthermore, the microchannelmay comprise more than two inlets and more than one mixing sections suchthat more than one reaction may occur within different sections of themicrochannel according predetermined manners. As discussed herein, themicrochannel is designed in consideration with its relations with theassociated magnet and microcoil and with the location of the disk andmagnetic patterns to achieve the desired NMR or ESR.

In the embodiments of the invention, device and the detection unit canaccommodate a wide range of sample volume, including very small amountof samples. In one embodiment, the space for holding a liquid sample hasa volume of from about 1.0 nL to about 1.0 mL. In another embodiment,the space has a volume of from about 10 nL to about 10 μL. As understoodby a person skilled in the art, actual sample volumes will depend on thenature of the analysis to be conducted, in addition to the limitation ofthe device. Also, the volume of the sample that actually experiences theNMR or ESR phenomenon will depend on the design and dimension of thedevice as well as the analysis being conducted. In cases where the spacefor holding the liquid sample is a microchannel having two inlets andone outlet, the total sample holding space may be substantially largerthan the volume that is under NMR or ESR effect. For example, the totalchannel volume, excluding the inlets and outlet, may be about 1.0 μmwhile the volume under the microcoil, or the NMR or ESR effect, may beabout only 10 nL to 100 nL.

In one embodiment of the invention, the magnet, whether on or near thesubstrate, comprises a permanent magnet or an electromagnet. Asdisclosed herein, the permanent magnet or electromagnet generates astatic magnetic field across at least a portion of the space for holdinga liquid sample. Materials suitable for use as the permanent magnet orelectromagnet include permanent magnetic materials, ferromagneticmaterials, paramagnetic materials, and non-magnetic metals. When aferromagnetic material is used for the magnet, an external magneticfield is used to magnetize the material. Further, when either aferromagnetic or non-magnetic material is used for the magnet, anelectrical current is applied to the material to create anelectromagnet. In one embodiment of the invention, the magnet comprisesone or more of iron, nickel, cobalt, a rare-earth material such asneodymium, copper, aluminum, and mixtures thereof. More specifically, aNeodymium-Iron-Boron type magnet can be used.

In the embodiment, the static magnetic field, together with theexcitation magnetic field generated by the rotating disk and magneticpattern, is capable of creating NMR or ESR within a liquid samplecontained in the space. In this regard, the magnet is “associated” withthe space for holding a liquid sample, meaning that the magnet is sosituated that it will achieve the desired effect. A number of factorswill be considered when associating the magnet with the space, includingwhether the magnet is on the substrate, the sizes and shapes of thedetection unit, the size of the magnet, the sizes and locations of theassociated space and microcoil, the size, location and rotation speed ofthe disk and the magnetic pattern, the desired strength of the staticmagnetic field, and the volume within which the desired NMR or ESR willbe effectuated. In a specific embodiment, the magnet is placed near oradjacent to the space for holding a liquid sample. The specific type,size, strength, and location of the magnet on the substrate will bedetermined based on the specific analysis desired by a person skilled inthe art.

Embodiments of the present invention can be adapted to perform eitherNMR or ESR analysis. As disclosed herein, ESR occurs according tosimilar principles as NMR, except that unpaired electron spins aredetected in ESR, whereas unpaired nuclear spins are detected in NMR.Therefore, ESR and NMR spectra reveal different aspects of the target'sstructure. Unpaired electrons are rare in natural states as most stablemolecules, such as those in nature biological samples, have aclosed-shell configuration without a suitable unpaired spin, ESR has notbeen as widely used as NMR in analytical chemistry and medicaldiagnostics. In addition, ESR sometimes requires spin labeling orartificial introduction of unpaired electron spins. However, ESR isuseful in detecting species that have unpaired electrons, such as freeradical, if the species is an organic molecule, or contain transitionmetal ions if the species is an inorganic complex.

As disclosed herein, ESR has higher sensitivities as compared to NMR andit requires a lower strength for the static magnetic field. A staticmagnetic field strength of less than 0.5 Tesla (T) is usually requiredfor ESR, whereas a strength of larger than 0.5 T, or more typicallylarger than 1.0 T, is required for NMR. On the other hand, ESR has ahigher resonance frequency, usually larger than 1.0 GHz, as compared toless than 500 MHz for NMR. Also, for NMR, pulse wave measurement andtechnique are commonly used and that traditional continuous NMR is rare.For ESR, both continuous and pulse wave measurement and technique areused. Although the embodiments of the invention focus on pulse wavemeasurement, the embodiments also encompass continuous wave techniques.As disclosed herein, the differences between ESR and NMR means thatmaterials selections are different for an ESR or NMR device, and thatdifferent electronic circuitries are required to detect, collect, and/orprocess the signals from the ESR or NMR.

In a specific embodiment, the magnet is capable of generating a staticmagnetic field strength of from about 0.01 Tesla (T) to about 30 T, ormore specifically, from about 0.05 T to about 10 T. As disclosed herein,for NMR, a static magnetic field strength of 0.1 T or more may berequired. Usually, a static magnetic field strength of 0.5 T or more isused in an NMR. Thus, in a specific embodiment, the magnet is capable ofgenerating a static magnetic field strength of from about 0.1 T to about5.0 T. In another specific embodiment, the magnet is capable ofgenerating a static magnetic field strength of from about 0.1 T to about2.0 T. Also as disclosed herein, for ESR, a static magnetic fieldstrength of 1.0 T or less may be required. Usually, a static magneticfield strength of 0.5 T or less is used in an ESR. Thus, in a specificembodiment, the magnet is capable of generating a static magnetic fieldstrength of from about 0.1 T to about 0.5 T. In another specificembodiment, the magnet is capable of generating a static magnetic fieldstrength of from about 0.3 T to about 0.5 T.

In the embodiments of the invention, many conductive materials aresuitable for the microcoil. In the embodiments, the microcoil can beused for either detecting the NMR or ESR signals or generating anexcitation magnetic field across at least a portion of the sampleholding space. The selection of materials for the microcoil depends onseveral factors including the type and size of the coil, the desiredstrength of NMR or ESR signals to be detected, the size and location ofspace for holding a liquid sample, the shape, size and nature of thesubstrate, the nature and location of the magnet, and the location androtating speed of the disk and magnetic pattern. The conductivity of thematerial is important to the selection. In one embodiment of theinvention, the microcoil comprises copper, aluminum, gold, silver, or amixture thereof.

In the embodiments of the invention, the microcoil is “associated” withthe space for holding a sample, meaning that meaning that the microcoilis so situated that it will achieve the desired effect of detecting NMRor ESR within at least a portion of the space. A number of factors willbe considered when associating the microcoil with the space, includingthe type and size of the microcoil, the sizes and locations of theassociated space and magnet, the desired strength of the static magneticfield and the excitation magnetic field, and the volume within which thedesired NMR or ESR will be effectuated. In a specific embodiment, themicrocoil is placed near or adjacent to the space for holding a liquidsample. The specific type, size, strength, and location of the microcoilon the substrate will be determined based on the specific analysisdesired by a person skilled in the art.

In one embodiment of the invention, the microcoil is a Solenoid typecoil. Solenoid type microcoils are multiple spiral wire loops, which mayor may not be wrapped around a metallic core. A Solenoid type microcoil,in addition to serving as a detection circuit, produces a magnetic fieldwhen an electrical current is passed through it and can createcontrolled magnetic fields. In the embodiment of the invention, theSolenoid type microcoil can produce a uniform magnetic field in apredetermined volume of the space.

In another embodiment of the invention, the microcoil is a planar spiralcoil, which is a microcoil with its windings substantially remained inan actual or imaginative plane. In the embodiment, the microcoil iswound around a center, which often is also the center; or on the sameaxis of the center, of the associated space for holding a liquid sampleand expands in a spiral like manner. The winding may take many differentforms, depending on the needs of the specific device and analysis. Forexample, the winding may take a generally circular, square, orrectangular shape.

In the embodiments of the invention, a planar microcoil is defined, inpart, by its inner-area dimension, the number of windings, and thewinding separation. The inner-area of a microcoil refers to the area atthe center of the microcoil where there is no winding and around whichthe microcoil is wound. The shape of the inner-area is usually notperfectly regular, although it is often similar to a circular,rectangular, or square shape. The dimension of the inner-area isdescribed herein by the length of the parameter of the area. The numberof windings as used herein refers to the number of times the microcoilis wound around the inner-area. As used herein, the winding separationrefers to the distance between two adjacent windings.

In one embodiment of the invention, the planar spiral microcoilcomprises an inner-area dimension of from about 10 μm to 10 mm, about 1to 100 windings, and a winding separation of about 1 μm to 500 μm. Inanother embodiment, the microcoil comprises an inner-area dimension offrom about 100 μm to 1.0 mm, about 1 to 30 windings, and a windingseparation of about 10 μm to 100 μm. In another specific embodiment, themicrocoil has a cross-section dimension of from about 0.01 μm to about100 μm.

In the embodiments of the invention, a disk having a magnetic pattern isused to generate an excitation magnetic field across at least a portionof a sample in the sample holding space. According to the embodiment,the disk can be rotated at a variety of different speeds. As the diskrotates, the magnetic pattern on the disk is able to generate magneticpulses within certain areas. Therefore, when placed near the sampleholding space, a rotating disk can generate an desired excitationmagnetic field across at least a portion of the space if the size androtating speed of the disk and the nature and location of the magneticpattern are controlled in a desired manner. Thus, according to theembodiments, it is no longer necessary to use microcoils and theassociated circuitry to generate excitation magnetic field to create anNMR or ESR.

According to an embodiment of the invention, the disk could be made frommany suitable materials, including but not limited to metals, polymers,silicon, and glass. The size and thickness of the disk will depend uponthe specific device and its applications desired. Specific types ofdisks commercially available and readily adaptable include opticaldiscs, compact discs (CDs), digital versatile discs (DVDs), laserdisc,magneto-optical discs, minidisk, digital multilayer disks, fluorescentmultilayer disc, universal media discs, floppy disks, and hard drivedisks. The disks should be adaptable to mechanical and/or electricalcontrols such that they are able to rotate at controlled and desiredspeeds and be placed at desired locations. Further, magnetic materialsshould be able to be attached to the disks to form desired patterns.

In a specific embodiment, the disk comprises metal, polymer, silicon,glass, or a combination thereof. More specifically, the disk maycomprise aluminum, gold, copper, silver, cobalt, platinum, chromium,iron, a metal oxide, a polycarbonate, or a combination thereof.According to another embodiment, the disk is capable of storing datarelated to the NMR or ESR signal.

In another embodiment, the disk has a diameter ranging from about 1.0 cmto about 20 cm. More specifically, the disk has a diameter ranging fromabout 2.0 cm to about 10 cm. The thickness of the disk may range fromabout 0.1 mm to about 10 mm. In one embodiment, the thickness of thedisk ranges from about 1.0 mm to about 3.0 mm.

According to the embodiments of the invention, a magnetic pattern on adisk encompasses one or more of magnetic materials, or magnetic members,attached on a surface of the disk according to a pre-designed fashion.The magnetic members are usually discretely located on the surface,although they may also be interconnected in certain situations. Amagnetic member is usually small in size and can be defined by the areathat it occupies on the surface and its thickness, or the biggestperpendicular distance from any point on the member to the surface ofthe disk. A magnetic member is further defined by its distance to thecenter of the disk. Thus, when the disk is rotating, a certain magneticmember will rotate at a specific linear speed, based on the rotatingspeed of the disk and the member's distance from the center of the disk.The rotation will also create a unique circular “track” for a specificmagnetic member. As discussed herein, a rotating magnetic member iscapable of generating an excitation magnetic field within a sample in asample holding space that is on or near the track of the magneticmember.

In one embodiment of the invention, the magnetic pattern comprises oneor more magnetic members attached to a surface of the disk. According tothe embodiment, each of the magnetic members occupies an area on thesurface of the disk and has a thickness measured by the biggestperpendicular distance from a point on the magnetic member to thesurface of the disk. The nature, numbers, and locations of the magneticmembers define the magnetic pattern on the disk. For example, a specificmagnetic pattern may comprise one, two, three, or more magnetic memberslocated at pre-determined locations on the disk to achieve the goal ofgenerating desired excitation magnetic fields across different sampleholding spaces or different locations in a single sample holding space.

In one embodiment, the magnetic members comprise iron, nickel, cobalt,copper, aluminum, platinum, palladium, or a combination thereof. Inanother embodiment, the magnetic members comprise a cobalt alloy, acobalt and platinum alloy, or a cobalt and palladium alloy.

In another embodiment, the area occupied by a magnetic member on a diskhas a circular, rectangular, or cubical shape. In a specific embodiment,the area has a dimension ranging from about 1.0 nm to about 1000 mm.More specifically, the area has a dimension ranging from about 10 nm toabout 5000 μm, or from about 0.1 μm to about 1000 μm.

In one embodiment, the thickness of a magnetic member ranges from 1.0 nmto about 500 mm. In another embodiment, the thickness ranges from about10 nm to about 50 mm, or from 0.1 μm to about 1000 μm.

In the embodiments of the invention, a magnetic member is furtherdefined by its location on the disk, specifically, its distance from thecenter, or the imaginative center, of the disk. In one embodiment, thereis only one magnetic member located at a given distance from the centerof the disk. In another embodiment, there are two or more magneticmembers located at a given distance from the center of the disk. Instill another embodiment, two or more magnetic members are located atdifferent distances from the center of the disk and form a straight linewith the center of the disk.

In an embodiment of the invention, the distances from the magneticmembers to the center of the disk range from about 1.0 cm to about 20cm. In another embodiment, the distances from the magnetic members tothe center of the disk range from about 2.0 cm to about 10 cm.

According to another embodiment of the invention, existing technologiescan be used to construct the devices of the invention. For example,silicon process technologies can be used to construct or fabricate thedetection unit of the embodiments of the invention, such that the sampleholding space, microcoil can be constructed on a substrate that may alsocomprise an integrated circuit and/or microfluidic mechanisms. Inanother embodiment, servo-mechanical components and mechanisms can beused to control the location and movement of the disk and the detectionunit such that the desired static and excitation magnetic fields and theassociated NMR or ESR effects are generated.

FIGS. 1-4 illustrate various embodiments of the invention. In FIG. 1, adevice comprising a detection unit, or resonance detector unit, and arotating disk with magnetic patterns is shown. As illustrated, thedetection unit comprises a sample holding space, a permanent magnet, anda microcoil. The rotating disk with magnetic patterns is situated nearand over the detection unit and is placed on a spindle, such as adisk-drive spindle, at its center. The detection unit comprises a pairof permanent magnets located nest to the sample holding space, as shownand explained in more detail in FIGS. 2 and 3. The detection unit isfurther connected with a servo-control unit, which controls the locationand movement of the detection unit, and a signal processing unit, whichcollects, analysis, and/or process signals detected by the detectionunit.

As shown in FIG. 1, when the disk rotates or spins around the spindle,one or more of the magnetic members of the magnetic patterns on the diskwill appear directly over the sample holding space. As shown in moredetail in the lower left box of FIG. 1, the specific magnetic memberappears near and directly over the sample holding space at times A, Band C and generates a magnetic field. Thus, the rotation of the diskover the detection unit and the sample holding space and the periodicappearance of the specific magnetic member over the space, at a desiredfrequency, generate a magnetic pulse or excitation in the space, asillustrated in the lower right box of FIG. 1. As a result, a samplecontained in the sample holding space, already under a strong staticmagnetic field created by the permanent magnets, experiences NMR or ESReffects, which can be detected and captured by the microcoil in thedetection unit and further analyzed and/or processed.

FIGS. 2 and 3 illustrate a more detailed cross-section view and top-downview of an embodiment of the detection unit, or the resonance detectorunit. As shown, the unit includes a space for holding a sample, such asa liquid sample, an associated microcoil, and a pair of built-inpermanent magnets that generate a static magnetic field, Bo, across thesample holding space, which may contain a bio-molecular sample. As shownin FIGS. 2 and 3, the magnets are attached to a substrate through aninsulating layer and are located next to the sample holding space. Aplanar microcoil is located just beneath the sample holding space andwound around the space, the center of which serves as an imaginativecenter of the windings. The windings of the microcoil are imbedded inthe insulating layer, which is attached to the substrate. As shown inthe figures, the microcoil is wound in a square shaped and spiral likemanner around the center. As disclosed herein, the microcoil may also bewound around the center in circular shaped manners.

FIG. 4 further illustrates an embodiment of the invention. A devicecomprising a detection unit, or resonance detector unit (RUD), and adisk with magnetic patterns is shown. For simplicity, only one magneticmember of the magnetic pattern on disk is shown. As illustrated, whenthe disk rotates, the magnetic member rotates on a track that intersectswith the sample holding space on the detection unit. The lower graphillustrates the magnetic flux density over the detection unit (RDU),especially the sample holding space of the RDU, as a function of time.

As shown in FIG. 4, assuming a starting time at to, when the magneticmember is approximately a quarter of a rotation from the RDU, and asingle rotation, or period, time of T, the magnetic excitation anddetection are shown in the graph. The frequency of the excitation, whenthe magnetic member is directly over the sample holding space, dependson linear travel speed of the magnetic member. As discussed herein, thelinear travel speed of a specific magnetic member on a disk depends onthe rotation speed of the disk, e.g., as measured by rpm, and thedistance from the member to the center of the disk. Thus, for a givendisk, a specific magnetic pattern can be designed so that, according tothe rotating speed of the disk and the distances of the magnetic membersto the center of the disk, the magnetic members of the magnetic patternon disk can produce distinct excitation magnetic fields across distinctsample holding spaces or distinct regions in a sample holding space.

Another embodiment of the invention relates to a device comprising adetection unit that comprises an array of sample holding spaces forholding liquid samples. In a specific embodiment, each of the spaces hasa volume of from about 10 nL to about 100 μL. In one embodiment, themagnetic pattern on disk is capable of generating an excitation magneticfield across at least a portion of the space; and a magnet capable ofgenerating a static magnetic field across at least two of the spaces.According to another embodiment, the magnet is capable of generating astatic magnetic field across the at least two spaces.

According to one embodiment, in which the detection unit comprises anarray of sample holding spaces, the static magnetic field and theexcitation magnetic field are capable of creating NMR or ESR within asample contained in each of the at least two of the spaces. In anotherembodiment, each of the at least two of the spaces is associated with amicrocoil capable of detecting signals from the NMR or ESR. The samplemay be a liquid, gel, solid, gas, or mixture. Variations of theembodiment encompass a detection unit, or substrate, that also comprisesmicroarray or macroarray of microcoils and the associated sample holdingspace or spaces on the substrate. The microcoils and the spaces may beformed on or near the surface of the substrate using methods disclosedherein.

According to one embodiment, the detection unit further comprises amagnet capable of generating a static magnetic field across at least twoof the spaces for holding a sample. In the embodiment, the magnet isintegrated into the substrate of the detection unit and is so designedand situated that it can generate the required static magnetic fieldacross a portion or the whole of the sample holding spaces.Alternatively, according to another embodiment, the magnet is locatednear the detection unit. In the embodiments, suitable conventional NMRor ESR magnets may be used according to the design of the device and thespecific analysis to be carried out.

Suitable magnets include permanent magnets or electromagnets. Asdisclosed herein, the permanent magnet or electromagnet generates astatic magnetic field across at least a portion of the spaces forholding a liquid sample. Materials suitable for use as the permanentmagnet or electromagnet include permanent magnetic materials,ferromagnetic materials, paramagnetic materials, and non-magneticmetals. When a ferromagnetic material is used for the magnet, anexternal magnetic field is used to magnetize the material. Further, wheneither a ferromagnetic or non-magnetic material is used for the magnet,an electrical current is applied to the material to create anelectromagnet. In one embodiment of the invention, the magnet comprisesone or more of iron, nickel, cobalt, a rare-earth material such asneodymium, copper, aluminum, and mixtures thereof. More specifically, aNeodymium-Iron-Boron type magnet can be used.

In the embodiment, the static magnetic field, together with theexcitation magnetic field generated by the magnetic pattern on disk, iscapable of creating NMR or ESR within a liquid sample contained in eachof at least two of the spaces. In this regard, the magnet is“associated” with the spaces, meaning that the magnet is so situatedthat it will achieve the desired effect in the at least two spaces. Anumber of factors will be considered when associating the magnet withthe space, including the size of the magnet, the sizes and locations ofthe associated spaces, microcoils, the magnetic pattern on disk, thedesired strength of the static magnetic field, and the volume withinwhich the desired NMR or ESR will be effectuated. In a specificembodiment, the magnet is placed near or adjacent to the spaces forholding liquid samples. The specific type, size, strength, and locationof the magnet on the substrate will be determined based on the specificanalysis desired by a person skilled in the art.

In one embodiment, the detection unit comprises silicon, glass, apolymeric material, metal, or a combination thereof. In anotherembodiment, the detection unit comprises an integrated circuit, a MEMSdevice, a microarray, a macroarray, a multi-well plate, a microfluidicdevice, or a combination thereof. Further, the detection unit maycomprise circuitry that is capable of amplifying or processing the NMRor ESR signals detected by the microcoils.

In a specific embodiment of the invention, the detection unit, orsubstrate, comprises an array of spaces for holding samples and whereineach of at least a portion of the microcoils is capable of generating anexcitation magnetic field across one of the spaces. According to theembodiment, the substrate comprises an array of sample holding spacesand their associated microcoils. The design of the sample holdingspace/microcoil array is made according to the specific analysis to becarried out. For example, specific samples can be put into the sampleholding spaces, and analysis can be carried out with the help of themagnetic pattern on disk and the associated microcoils, as disclosedherein.

In another embodiment of the invention, the magnetic pattern on disk iscapable of generating an excitation magnetic field across a plurality ofthe spaces, or distinct portions of one or more of the spaces. Accordingto the embodiment, the spaces for holding a liquid sample are associatedwith the magnetic pattern on disk and with an array of microcoils. Themagnetic patter is designed such that a magnetic member is associatedwith a distinct sample holding space or a distinct portion of, or a spoton, a sample holding space. The design of the microcoil array and thespace is made according to the specific analysis. For example, probe orcapture molecules can be attached to or associated with the individualmicrocoils to carry out specific DNA or protein analysis, as disclosedherein.

According to another embodiment of the invention, each of at least aplurality of the spaces for holding samples comprises a reservoir, amicrochannel, an opening, a surface, or a combination thereof. Theembodiment accommodates a variety of applications in which an NMR or ESRis involved. For example, the sample holding space may be a reservoir,an opening void, or a surface that can hold a liquid sample. In suchcases, the sample holding space may be an open reservoir or surface, ora substantially closed void with an opening for sample input. The designof the space depends not only on the specific analysis to be done, butalso on how to best situate and design the sample holding space inrelation to the associated magnet and microcoil, as discussed herein.

According to the embodiment, the space for holding a liquid sample mayalso be the whole or part of a microchannel fabricated on the substrate.Depending on the specific requirement, the microchannel may be open (atrench) or closed. The microchannel typically comprises an inlet and anoutlet, but may also comprise other opening for fluidic communication.In another embodiment, the microchannel comprise two or more inlets andat least one outlet such that different reactants may be introduced intothe channel from different inlets and mixed at a mixing section withinthe channel for specific chemical reaction. Furthermore, themicrochannel may comprise more than two inlets and more than one mixingsections such that more than one reactions may occur within differentsections of the microchannel according predetermined manners. Asdiscussed herein, the microchannel is designed in consideration with itsrelations with the associated magnet and microcoil to achieve thedesired NMR or ESR.

In the embodiments of the invention, the integrated on-chip NMR or ESRdetection unit or substrate can accommodate a wide range of samplevolume, including very small amount of samples. In one embodiment, thespace for holding a liquid sample has a volume of from about 1.0 nL toabout 10 mL, or more specifically, from about 0.1 μL to about 5.0 mL. Inthe embodiment, the sample holding space may be associated with aspecifically designed magnetic pattern on disk, each magnetic member ofwhich is capable of generating an excitation magnetic field across adistinct portion or spot on the space. In another embodiment, thesubstrate comprises an array of sample holding spaces and each of thespaces has a volume of from about 10 nL to about 10 μL. As understood bya person skilled in the art, actual sample volumes will depend on thenature of the analysis to be conducted, in addition to the limitation ofthe device. Also, the volume of the sample that actually experiences theNMR or ESR phenomenon will depend on the design and dimension of thedevice as well as the analysis being conducted.

Another embodiment of the invention relates to a method of performing anNMR or ESR analysis. The method comprises: (1) providing a device thatcomprises a detection unit, a magnet, and a disk, wherein the detectionunit comprises a microcoil and a space for holding a sample and the diskcomprises a magnetic pattern; (2) providing a sample within the space;(3) using the magnet to generate a static magnetic field across at leasta portion of the sample; (4) rotating the disk to generate an excitationmagnetic field across at least a portion of the sample; and (5)detecting signals from the sample by using the microcoil.

In one embodiment, the static magnetic field and the excitation magneticfield create Nuclear Magnetic Resonance (NMR) or Electron Spin Resonance(ESR) within the sample, which may be in a liquid, gel, solid, gas, or amixture state. In another embodiment, the method further comprisesamplifying, processing, or analyzing the signals detected by themicrocoil. The detection unit may comprise a circuitry capable ofdetecting, processing, or analyzing the signals from the sample.According to another embodiment, the method comprises generating an NMRor ESR spectroscopy of the liquid sample, or storing data related to theNMR or ESR signals in the disk. Also, the providing of the liquid samplewithin the space comprises introducing two or more different samplesinto the space.

In one embodiment of the NMR or ESR analysis method, the providing ofthe device comprises using a servomechanism to control the location andmovement of the detection unit, the magnet, and/or the disk. In theembodiment, conventional servomechanisms can be used such that thearrangement of the detection unit, including the sample holding spaceand microcoil, the magnet, and the disk with magnetic pattern is suitedto create the desired NMR or ESR for a sample in the sample holdingspace.

According to one embodiment, the rotating of the disk is at a speed offrom about 10 rpm to about 2000 rpm. More specifically, the rotating ofthe disk is at a speed of from about 100 rpm to about 1000 rpm, or fromabout 200 rpm to about 600 rpm.

In the embodiment, samples suitable for the NMR or ESR analysis maycontain any types of substances that can be analyzed through an NMR orESR analysis. The substances include organic or inorganic molecules,macromolecule, biological cells, biomolecules such as proteins,peptides, nucleotides, polynucleotides, DNAs, RNAs, and substancescontaining free radicals radical or transition metal ions. Further, thevolume of the sample may range from 1.0 nL to about 1.0 mL or, morespecifically, from 10 nL to about 10 μL.

In one embodiment of the NMR or ESR analysis method, the detection unitcomprises an array of spaces for holding samples and the magneticpattern on disk comprises a plurality of magnetic members. According tothe embodiment, each of at least a portion of the magnetic members isused to generate an excitation magnetic field across at least aplurality of the sample holding spaces or a plurality of distinctportions of a sample holding space. In another embodiment, the detectionunit comprises an array of microcoils associated with the array ofsample holding spaces and each of at least a portion of the microcoilsis used to detect NMR or ESR signals from a sample in one of the spaces.

According to one embodiment, the detection unit or substrate furthercomprises a magnet capable of generating a static magnetic field acrossat least a plurality of the sample holding spaces. In the embodiment,the magnet is integrated into the substrate and is so designed andsituated that it can generate the required static magnetic field acrossa portion or the whole of the plurality of sample holding spaces.Alternatively, according to another embodiment, the magnet is placednear the detection unit. In the embodiments, suitable conventional NMRor ESR magnets may be used according to the design of the device and thespecific analysis to be carried out. Further, suitable magnets includepermanent magnets or electromagnets.

According to one embodiment, each of at least a portion of themicrocoils or sample holding spaces on the detection unit is associatedwith a biomolecule. In a specific embodiment, the biomolecule a DNA andis capable of hybridizing with a complementary DNA. NMR signals from theDNA hybridization is detected by at least a portion of the microcoils.

The above embodiments of the invention may also be regarded asintegrating the plurality of microcoils and, in certain cases, thespaces for holding samples into a macroarray or microarray, such as aDNA array. In the embodiments, as discussed herein, multiple microcoilsand the associated spaces are formed on or near the surface of thesubstrate and form an array to perform certain analysis. Whenincorporated into a DNA array, the microcoils or sample holding spacesare further associated with or attached to the probe molecule or DNAprobe, such that, when the DNA target and the probe hybridize, the wholeor part of the hybridized molecule can be detected through NMRmicrocoils.

As disclosed herein, compound and molecules suitable for the NMR or ESRanalysis by the embodiments of the invention include proteins, peptides,and, specifically, nucleic acids (DNA and RNA), which can formdouble-stranded molecules by hybridization, that is, complementary basepairing. For example, in an embodiment of the invention, a molecularprobe, such as a DNA probe, is associated with or attached to a samplereservoir or microcoil, which is located near or on the surface of, orotherwise integrated into, the substrate. The specificity of nucleicacid hybridization is such that the detection of molecular and/ornanomaterials binding events can be done through measurements of the NMRsignals by the microcoils and other integrated or external components.This specificity of complementary base pairing also allows thousands ofhybridization to be carried out simultaneously in the same experiment ona DNA chip (also called a DNA array).

Molecular probes are immobilized on the surface of individual orindividually addressable reservoirs and/or microcoils through surfacefunctionalization techniques. The microcoils allow the NMR or ESRsignals to be detected and/or measured. The probe in a DNA chip isusually hybridized with a complex RNA or cDNA target generated by makingDNA copies of a complex mixture of RNA molecules derived from aparticular cell type (source). The composition of such a target reflectsthe level of individual RNA molecules in the source. The NMR or ESRsignals resulting from the binding events from the DNA spots of the DNAchip after hybridization between the probe and the target represent therelative expression levels of the genes of the source.

The DNA chip could be used for differential gene expression betweensamples (e.g., healthy tissue versus diseased tissue) to search forvarious specific genes (e.g., connected with an infectious agent) or ingene polymorphism and expression analysis. Particularly, the DNA chipcould be used to investigate expression of various genes connected withvarious diseases in order to find causes of these diseases and to enableaccurate treatments.

Using embodiments of the invention, one could find a specific segment ofa nucleic acid of a gene, i.e., find a site with a particular order ofbases in the examined gene. This detection could be performed by using adiagnostic polynucleotide made up of short synthetically assembledsingle-chained complementary polynucleotide—a chain of bases organizedin a mirror order to which the specific segment of the nucleic acidwould attach (hybridize) via A-T or G—C bonds.

The practice of the embodiments of the invention may employ, unlessotherwise indicated, conventional techniques of organic chemistry,polymer technology, molecular biology (including recombinanttechniques), cell biology, biochemistry, and immunology, which arewithin the skill of the art. Such conventional techniques includepolymer array synthesis, hybridization, ligation, detection ofhybridization using a label. Specific illustrations of suitabletechniques can be had by reference to the example herein below. However,other equivalent conventional procedures can, of course, also be used.

Another embodiment of the invention relates to a method of making an NMRor ESR device. The method comprises: (1) fabricating a space for holdinga sample on a substrate; (2) fabricating a microcoil on the substrate,the microcoil being associated with the space; (3) attaching a magnet tothe substrate, the magnet being capable of generating a static magneticfield across at least a portion of the space; and (4) fabricating amagnetic pattern on a disk, the magnetic pattern being capable ofgenerating an excitation magnetic field across at least a portion of thespace. According to the embodiment, the static magnetic field and theexcitation magnetic field are capable of creating Nuclear MagneticResonance (NMR) or Electron Spin Resonance (ESR) within a samplecontained in the space and the microcoil is capable of detecting signalsfrom the NMR or ESR.

In one embodiment of the invention, fabricating of the sample holdingspace or fabricating of the microcoil comprises combining two or moresolid support to form the substrate. According to the embodiment, thesample is a liquid, a gel, a solid, a gas, or a mixture thereof. Inanother embodiment, the method for fabricating a device furthercomprises forming circuitry on the substrate such that the circuitry iscapable of amplifying or processing the NMR or ESR signals detected bythe microcoil. Also, the method may further comprise providingservo-mechanical components to control the locations and movements ofthe substrate, the magnet, and the disk.

The NMR or ERS devices of the embodiments of the invention may be formedby any suitable means of manufacture, including semiconductormanufacturing methods, microforming processes, molding methods, materialdeposition methods, etc., or any suitable combination of such methods.In certain embodiments one or more of the magnets, microcoils, andcircuitries on the detection unit, or substrate, may be formed viasemiconductor manufacturing methods on a semiconductor substrate. Thinfilm coatings may be selectively deposited on portions of the substratesurface. Examples of suitable deposition techniques include vacuumsputtering, electron beam deposition, solution deposition, and chemicalvapor deposition. The coatings may perform a variety of functions. Forexample, the coatings may be used to increase the hydrophilicity of asurface or to improve high temperature properties. Conductive coatingsmay be used to form the microcoils. Coatings may be used to provide aphysical barrier on the surface, e.g. to retain fluid at specific siteson the surface.

In one embodiment of the invention, the substrate is made throughcombining two or more smaller substrates or solid support. Specifically,the fabricating of the sample holding space, the attaching of themagnet, or the fabricating of the microcoil may involve combining two ormore smaller substrates to form the substrate or detection unit.

The substrate used in the embodiments of the invention may comprisevarious materials including, but not limited to silicon, glass, metal,and polymeric material. According to the embodiments, the substratecomprises an integrated circuit, a MEMS device, a microarray, amacroarray, a multi-well plate, a micro fluidic device, or a combinationthereof.

In on embodiment of the invention, the space for holding a samplecomprises a reservoir, a microchannel, an opening, a surface, or acombination thereof. In another embodiment, the magnet comprises apermanent magnet or an electromagnet. The magnet may be placed near oradjacent to the space for holding a liquid sample. According to anotherembodiment, the microcoil comprises of copper, aluminum, gold, silver,or a mixture thereof. The microcoil is placed near or adjacent to thespace for holding a liquid sample. Either Solenoid type or a planarspiral microcoil may be used.

In another embodiment of the invention, fabricating of the magneticpattern on the disk comprises attaching one or more magnetic members ona surface of the disk. Further, the fabricating of the space maycomprise fabricating an array of spaces for holding liquid samples onthe substrate.

In a specific embodiment, fabricating of the magnetic pattern comprisesattaching a plurality of magnetic members on a surface of the disk.According to the embodiment, the magnetic members are capable ofgenerating an excitation magnetic field across each of at least two ofthe spaces. More specifically, fabricating of the microcoil comprisesfabricating a microcoil associated with each of the at least two spacessuch that the microcoil is capable of detecting the NMR or ESR signalsfrom a liquid sample contained in the space.

As disclosed herein, silicon is a suitable material for attaching othermaterials, such as metal or magnetic materials and forming structures,such as openings and microchannels coupled with microelectronics orother microelectromechanical systems (MEMS). It also has good stiffness,allowing the formation of fairly rigid microstructures, which can beuseful for dimensional stability. In a specific embodiment of theinvention, the detection unit or substrate comprises an integratedcircuit (IC), a packaged integrated circuit, and/or an integratedcircuit die. For example, the substrate may be a packaged integratedcircuit that comprises a microprocessor, a network processor, or otherprocessing device.

In another embodiment, the method further comprises forming circuitry onor within the detection unit that is capable of amplifying or processingthe NMR or ESR signals detected by the microcoil. The substrate for thedetection unit may be constructed using, for example, a ControlledCollapse Chip Connection (or “C4”) assembly technique, wherein aplurality of leads, or bond pads are internally electrically connectedby an array of connection elements (e.g., solder bumps, columns).

In another embodiment of the invention, the fabricating of the microcoilcomprises fabricating an array of microcoils capable of detecting NMR orESR signals from at least a portion of the space. Further, each of atleast a portion of an array of microcoils on the detection unit iscapable of detecting NMR or ESR signals from a distinct portion of thespace. In the embodiment, the substrate may comprise an array of spacesfor holding liquid samples and each of at least a portion of themicrocoils is capable of detecting NMR or ESR signals across one of thespaces. Thus, the embodiment encompasses fabricating an array of sampleholding spaces each in association with a microcoil.

In the embodiments of the invention, the magnet may be attached eitherto or near the detection unit. The magnet, whether being a permanentmagnet or an electromagnet, may be attached to a silicon substratethrough an adhesive layer to form the detection unit. The adhesive layercan also be referred to and regarded as a seed layer used to join themagnet with the substrate. Any suitable adhesive materials may be usedas the adhesive layer. In one embodiment of the invention, the adhesivelayer comprises one or more of titanium, tantalum, platinum, andpalladium.

According to the embodiments of the invention, microcoils can befabricated on or within the substrate using a number of techniques,including etching, bonding, annealing, adhering/seeding, lithography,molding, and printing. Physical vapor deposition (PVD) and chemicalvapor deposition (CVD) can also be used. In one embodiment, microcoilsare fabricated on an oxidized silicon substrate by electroplating metalsinside a deep photoresist mold and then passivated using an epoxy basedresist.

The detection unit or substrate of the embodiments of the presentinvention is suitable for forming openings, voids, surfaces, ormicrochannels thereon for holding fluid and fluidic communications. Thesample holding space may be open or closed along. Various methods may beused to form the sample holding space on the substrate. For example, areservoir or an open microchannel can be fabricated on a siliconsubstrate by etching methods known to those skilled in the art. Closedmicrochannels can be formed by sealing the open channels at top usingmethods such as anodic bonding of glass plates onto the openmicrochannels on the silicon substrate.

According to one embodiment of the invention, to fabricate amicrochannel on a silicon substrate, a photoresist (positive ornegative) is spun onto the silicon substrate. The photoresist is exposedto UV light through a high-resolution mask with the desired devicepatterns. After washing off the excessive unpolymerized photoresist, thesilicon substrate is placed in a wet chemical etching bath thatanisotropically etches the silicon in locations not protected by thephotoresist. The result is a silicon substrate in which microchannelsare etched. If desired, a glass cover slip is used to fully enclose thechannels. Also, holes are drilled in the glass to allow fluidic access.For straighter edges and a deeper etch depth, deep reactive ion etching(DRIE) can be used as an alternative to wet chemical etching.

In another embodiment of the invention, microchannels may be formed on asilicon substrate using the following method. A seed layer of a metal,such as copper, is deposited over a surface of the substrate. Anysuitable blanket deposition process may be used to deposit the seedlayer of metal, such as physical vapor deposition (PVD), chemical vapordeposition (CVD), or other methods known to those skilled in the art. Alayer of a sacrificial material, such as a dielectric material or aphotoresist material, is then deposited over the seed layer. By removingthe sacrificial material, for example using chemical etch process orthermal decomposition process, a number of trenches in the sacrificiallayer is formed, and the seed layer is exposed in each of the trenches.Another layer of the metal, such as copper, is deposited over theexposed seed layer in the trenches. The metal layer extends overportions of the upper surface of the sacrificial layer; but gaps remainbetween the metal material layers extending from adjacent trenches andover the upper surface of the sacrificial layer. The sacrificial layeris removed, for example using chemical etching process or thermaldecomposition process, and regions from which the sacrificial layer hasbeen removed form channels in the metal layer. An additional layer ofthe metal is deposited over the upper surfaces of the metal layer toclose the gaps over the channels.

In the embodiments of the invention, reservoirs, openings andmicrochannels can be made by using soft lithography method with suitablematerials, such as silicon and polydimethylsiloxane (PDMS). With thesetechniques it is possible to generate patterns with critical dimensionsas small as 30 nm. These techniques use transparent, elastomeric PDMS“stamps” with patterned relief on the surface to generate features. Thestamps can be prepared by casting prepolymers against masters patternedby conventional lithographic techniques, as well as against othermasters of interest. Several different techniques are known collectivelyas soft lithography. They are as described below:

Near-Field Phase Shift Lithography. A transparent PDMS phase mask withrelief on its surface is placed in conformal contact with a layer ofphotoresist. Light passing through the stamp is modulated in thenear-field. Features with dimensions between 40 and 100 nm are producedin photoresist at each phase edge.

Replica Molding. A PDMS stamp is cast against a conventionally patternedmaster. Polyurethane is then molded against the secondary PDMS master.In this way, multiple copies can be made without damaging the originalmaster. The technique can replicate features as small as 30 nm.

Micromolding in Capillaries (MIMIC). Continuous channels are formed whena PDMS stamp is brought into conformal contact with a solid substrate.Capillary action fills the channels with a polymer precursor. Thepolymer is cured and the stamp is removed. MIMIC is able to generatefeatures down to 1 μm in size.

Microtransfer Molding ((TM). A PDMS stamp is filled with a prepolymer orceramic precursor and placed on a substrate. The material is cured andthe stamp is removed. The technique generates features as small as 250nm and is able to generate multilayer systems.

Solvent-assisted Microcontact Molding (SAMIM). A small amount of solventis spread on a patterned PDMS stamp and the stamp is placed on apolymer, such as photoresist. The solvent swells the polymer and causesit to expand to fill the surface relief of the stamp. Features as smallas 60 nm have been produced.

Microcontact Printing ((CP). An “ink” of alkanethiols is spread on apatterned PDMS stamp. The stamp is then brought into contact with thesubstrate, which can range from coinage metals to oxide layers. Thethiol ink is transferred to the substrate where it forms aself-assembled monolayer that can act as a resist against etching.Features as small as 300 nm have been made in this way.

Techniques used in other groups include micromachining of silicon formicroelectromechanical systems, and embossing of thermoplastic withpatterned quartz. Unlike conventional lithography, these techniques areable to generate features on both curved and reflective substrates andrapidly pattern large areas. A variety of materials could be patternedusing the above techniques, including metals and polymers. The methodscomplement and extend existing nanolithographic techniques and providenew routes to high-quality patterns and structures with feature sizes ofabout 30 nm.

Standard lithography on silicone wafer or silica glass could also beused to fabricate the devices of the embodiments of this invention.Reservoirs, openings and channels in the micrometer or nanometer scalecan be fabricated from the devices, and fluidic flow can be controlledby pressure gradient, electrical field gradient, gravity, and heatgradient. The binding complexes or sensors can also be separated byplanar device with a single a plurality of chambers, where the surfacesare modified with polymers (polyethylene glycol (PEG)-dramatizedcompounds) that can minimize non-specific binding. The solid support canbe inorganic material (e.g., glass, ceramic) or metal (e.g., aluminum).Biomolecules, proteins, antibodies, and/or nucleic acids can be coatedon the surface of the substrate for specific analyte binding.

In the embodiments of the invention, the microchannels formed on thesubstrate may be straight or have angles or curves along their lengths.The characteristics and layout of the microchannels are determined bythe specific applications the device is designed for. Although straightmicrochannels lining next to one another are a typical design formicrofluidic devices, the microchannels in the embodiments of theinvention may be designed in many different patterns to serve specificseparation and detection requirements. Specifically, the design of themicrochannels takes into consideration of the microcoils associated withthe microchannels such that the microcoils are capable of generatingexcitation magnetic fields across relevant portions of themicrochannels. Further, in the embodiments of the invention, thecross-section of the micro-channel so formed may be uniform or varyalong the channel's length, and may have various shapes, such asrectangle, circle, or polygon.

EXAMPLES

The rotation speed and dimension of the disk and magnetic patterns ondisk (MPoD) were obtained using model calculations. The calculations arebased upon the assumption that the duration of magnetic pulse is 10microsecond (μsec) and acquisition time is 160 millisecond (msec),similar as described in C. Massin et al., “High-Q Factor RF PlanarMicrocoils for Micro-Scale NMR Spectroscopy,” Sensors and Actuators A97-98, 280-283 (2002) work by C. Massin et al. The purpose of thecalculations is to determine the rotation speed and the length of theMPoD in the direction along the tracks.

Rotation Speed:

The rotation speed to allow for acquisition time long enough to capturethe decay process induced by magnetic resonance was determined. Assumingthere was only one sample holding space on the detection unit or RDU,one revolution of disk should take at least 160 msec. This relationshiptranslates into 375 rotations per minute (rpm):1 rotation per 160 msec=375 rpm

The disk should operate slower than 375 rpm. For comparison, typicalfloppy disk drive systems run at 300-360 rpm.

Magnetic Pattern Size:

The size of a magnetic member in the MPoD required to generate a 10μsec-long pulse was calculated. For simplicity of calculation, the trackat a distance of 3 cm from center of the disk was considered. Using therotation speed of 375 rpm at a track at 3 cm from center of disk center,a single rotation corresponds to 160 msec and 18.85 cm in linear traveldistance. During 10 μsec, a point on the track travels 11.78 μm. Thus,in order to obtain pulse with duration of 10 μsec, the magnetic membershould be about 11.78 μm in length (along the track).

Material Choice for MPoD:

Co alloy can be used to fabricate MPoD. Perpendicularly orientedCo-alloy film will provide excitation by generating magnetic pulse tothe sample of interest as disk rotates. Other magnetic films withperpendicular anisotropy can be also used. Such films include but arenot limited to Co/Pt and Co/Pd multi-layers.

The characteristics of some of the embodiments of the invention areillustrated in the Figures and examples, which are intended to be merelyexemplary of the invention. This application discloses several numericalrange limitations that support any range within the disclosed numericalranges even though a precise range limitation is not stated verbatim inthe specification because the embodiments of the invention could bepracticed throughout the disclosed numerical ranges. Finally, the entiredisclosure of the patents and pulications referred in this application,if any, are hereby incorporated herein in entirety by reference.

1. A device comprising: a detection unit comprising a space for holdinga sample and a microcoil; a magnet to generate a static magnetic fieldacross at least a portion of the space; and a disk comprising a magneticpattern to generate an excitation magnetic field across at least aportion of the space; wherein the static magnetic field and theexcitation magnetic field are capable of creating Nuclear MagneticResonance (NMR) or Electron Spin Resonance (ESR) within a liquid samplecontained in the space; and wherein the microcoil is capable ofdetecting signals from the NMR or ESR.
 2. The device of claim 1, whereinthe detection unit comprises silicon, glass, a polymeric material,metal, or a combination thereof.
 3. The device of claim 1, wherein thedetection unit comprises an integrated circuit, a MEMS device, amicroarray, a macroarray, a multi-well plate, a microfluidic device, ora combination thereof.
 4. The device of claim 1, wherein the detectionunit comprises circuitry capable of amplifying or processing the NMR andESR signals detected by the microcoil.
 5. The device of claim 1, whereinthe detection unit is connected to a circuitry capable of amplifying orprocessing the NMR and ESR signals detected by the microcoil.
 6. Thedevice of claim 1, wherein the sample is a liquid, a gel, a solid, agas, or a mixture thereof.
 7. The device of claim 1, wherein the spacefor holding a sample comprises a reservoir, a microchannel, an opening,a surface, or a combination thereof.
 8. The device of claim 7, whereinthe space for holding a sample is a microchannel, the microchannelhaving two or more inlets, at least one outlet, and at least one mixingsection where liquid samples introduced from the two or more inlets canbe mixed.
 9. The device of claim 1, wherein the space for holding asample has a volume of from about 1.0 nL to about 1.0 mL.
 10. The deviceof claim 9, wherein the space for holding a sample has a volume of fromabout 10 nL to about 10 μL.
 11. The device of claim 1, wherein themicrocoil comprises copper, aluminum, gold, silver, or a mixturethereof.
 12. The device of claim 1, wherein the microcoil is placed nearor adjacent to the space for holding a liquid sample.
 13. The device ofclaim 1, wherein the microcoil is a Solenoid type coil.
 14. The deviceof claim 1, wherein the microcoil is a planar spiral coil.
 15. Thedevice of claim 1, wherein the magnet is located on the detection unit.16. The device of claim 1, wherein the magnet comprises a permanentmagnet or an electromagnet.
 17. The device of claim 1, wherein themagnet is capable of generating a uniform static magnetic field across asubstantial portion of the space.
 18. The device of claim 1, wherein themagnet is capable of generating a static magnetic field strength of fromabout 0.01 Tesla (T) to about 30 T.
 19. The device of claim 1, whereinthe magnet is capable of generating a static magnetic field strength offrom about 0.5 T to about 5.0 T.
 20. The device of claim 1, wherein themagnet is capable of generating a static magnetic field strength of fromabout 0.01 T to about 0.5 T.
 21. The device of claim 1, wherein the diskcomprises metal, polymer, silicon, glass, or a combination thereof. 22.The device of claim 21, wherein the disk comprises aluminum, gold,copper, silver, cobalt, platinum, chromium, iron, a metal oxide, apolycarbonate, or a combination thereof.
 23. The device of claim 1,wherein the disk has a diameter ranging from about 1.0 cm to about 20cm.
 24. The device of claim 1, wherein the disk has a diameter rangingfrom about 2.0 cm to about 10 cm.
 25. The device of claim 1, wherein thedisk is capable of storing data related to the NMR or ESR signal. 26.The device of claim 1, wherein the magnetic pattern comprises one ormore magnetic members attached to a surface of the disk, each of themagnetic members occupying an area on the surface of the disk and havinga thickness measured by the biggest perpendicular distance from a pointon the magnetic member to the surface of the disk.
 27. The device ofclaim 26, wherein the magnetic members comprise iron, nickel, cobalt,copper, aluminum, platinum, palladium, or a combination thereof.
 28. Thedevice of claim 26, wherein the area has a circular, rectangular, orcubical shape.
 29. The device of claim 26, wherein the area has adimension ranging from about 1.0 nm to about 1000 mm.
 30. The device ofclaim 29, wherein the area has a dimension ranging from about 0.1 μm toabout 1000 μm.
 31. The device of claim 26, wherein the thickness rangesfrom 1.0 nm to about 500 mm.
 32. The device of claim 26, wherein thethickness ranges from 10 nm to about 1000 μm.
 33. The device of claim26, Wherein there is only one magnetic member located at a givendistance from the center of the disk.
 34. The device of claim 26,wherein there are two or more magnetic members located at a givendistance from the center of the disk.
 35. The device of claim 26,wherein the distances from the magnetic members to the center of thedisk range from about 1.0 cm to about 20 cm.
 36. The device of claim 26,wherein the distances from the magnetic members to the center of thedisk range from about 2.0 cm to about 10 cm.
 37. The device of claim 1,further comprising a servo-mechanical component capable of controllingthe location and movement of the detection unit, the magnet, or thedisk.
 38. The device of claim 1, wherein the detection unit comprises anarray of spaces for holding liquid samples.
 39. The device of claim 37,wherein the magnetic pattern on the disk is capable of generating anexcitation magnetic field across at least two of the spaces.
 40. Thedevice of claim 39, wherein the magnet is capable of generating a staticmagnetic field across the at least two spaces.
 41. The device of claim40, wherein the static magnetic field and the excitation magnetic fieldare capable of creating NMR or ESR within a liquid sample contained ineach of the at least two spaces.
 42. The device of claim 41, whereineach of at least two of the spaces is associated with a microcoilcapable of detecting the NMR or ESR signals.
 43. The device of claim 38,wherein each of the spaces has a volume of from about 10 nL to about 100μL.
 44. A method comprising: providing a device, the device comprising adetection unit, a magnet, and a disk, wherein the detection unitcomprises a space for holding a sample and a microcoil, and the diskcomprises a magnetic pattern; providing a sample within the space; usingthe magnet to generate a static magnetic field across at least a portionof the sample; rotating the disk to generate an excitation magneticfield across at least a portion of the sample; and detecting signalsfrom the sample by using the microcoil.
 45. The method of claim 44,wherein the static magnetic field and the excitation magnetic fieldcreate Nuclear Magnetic Resonance (NMR) or Electron Spin Resonance (ESR)within the liquid sample.
 46. The method of claim 44, further comprisingamplifying, processing, or analyzing the signals detected by themicrocoil.
 47. The method of claim 44, wherein the sample is a liquid, agel, a solid, a gas, or a mixture thereof.
 48. The method of claim 44,further comprising generating an NMR or ESR spectroscopy of the sample.49. The method of claim 44, further comprising storing data related tothe NMR or ESR signals in the disk.
 50. The method of claim 44, theproviding of the device comprises using a servomechanism to control thelocation and movement of the detection unit, the magnet, or the disk.51. The method of claim 44, wherein the rotating of the disk is at aspeed of from about 10 rpm to about 2000 rpm.
 52. The method of claim44, wherein the rotating of the disk is at a speed of from about 100 rpmto about 1000 rpm.
 53. The method of claim 44, wherein the providing thesample within the space comprises introducing two or more differentsamples into the space.
 54. A method comprising: fabricating a space forholding a sample on a substrate; fabricating a microcoil on thesubstrate, the microcoil being associated with the space; attaching amagnet to the substrate, the magnet being capable of generating a staticmagnetic field across at least a portion of the space; and fabricating amagnetic pattern on a disk, the magnetic pattern being capable ofgenerating an excitation magnetic field across at least a portion of thespace; wherein the static magnetic field and the excitation magneticfield are capable of creating Nuclear Magnetic Resonance (NMR) orElectron Spin Resonance (ESR) within a sample contained in the space;and wherein the microcoil is capable of detecting signals from the NMRor ESR.
 55. The method of claim 54, wherein fabricating of the space orthe fabricating of the microcoil comprises combining two or more solidsupport to form the substrate.
 56. The method of claim 54, wherein thesample is a liquid, a gel, a solid, a gas, or a mixture thereof.
 57. Themethod of claim 54, further comprising forming circuitry on thesubstrate, the circuitry being capable of amplifying or processing theNMR or ESR signals detected by the microcoil.
 58. The method of claim54, wherein fabricating the magnetic pattern on the disk comprisesattaching one or more magnetic members on a surface of the disk.
 59. Themethod of claim 54, wherein fabricating of the space comprisesfabricating an array of spaces for holding samples on the substrate. 60.The method of claim 59, wherein fabricating of the magnetic patterncomprises attaching a plurality of magnetic members on a surface of thedisk, the magnetic members being capable of generating an excitationmagnetic field across each of at least two of the spaces.
 61. The methodof claim 60, wherein fabricating of the microcoil comprises fabricatinga microcoil associated with each of the at least two spaces, themicrocoil being capable of detecting the NMR or ESR signals from aliquid sample contained in the space.
 62. The method of claim 54,further comprising providing servo-mechanical components to control thelocations and movements of the substrate, the magnet, and the disk.